The present invention pertains to testing, diagnosing and repairing printed wiring cards and more particularly to testing the bus leads of printed wiring cards which utilize bus structured components.
In the manufacture of complex bus structured printed wiring cards (PWC), the signal leads of each bus are closely spaced and cover a considerable of such printed wiring cards have elaborate bus structures on both sides of the PWC. These bus structures often pass beneath the components of the printed wiring card.
As a result of the wave solder process in the fabrication of printed wiring cards, these buses often contain solder shorts (unintended connection between the signal leads). One previous method of detecting such solder shorts include visual inspection with the aid of high magnification. Another method of detecting the shorts employs an ohm meter to check the resistance between a particular signal lead and every other signal lead to insure that no unintended connections have been made. These manual methods are time consuming and error prone.
Some printed wiring card testing involves the generation of complex computer generated algorithms. The process of generating the software which employs these algorithms is expensive for testing small numbers of various kinds of printed wiring cards.
Accordingly, it is the object of the present invention to provide an inexpensive, quick and relatively error free apparatus for automatically testing the bus structure of various printed wiring cards for electrical shorts.